High intensity discharge lamps such as a metal halide lamp, a high pressure sodium lamp and a mercury lamp selected from various types of electric-discharge lamps respectively have various merits such as a large quantity of light, a high luminous efficiency and a long lamp life. Therefore, in a prior art, each high intensity discharge lamp is used as an illuminating lamp or a street lamp disposed in indoor and outdoor facilities, a warehouse or a factory. To light this type of high intensity discharge lamp, it is required to apply a starting high voltage to the high intensity discharge lamp in a starting operation. Therefore, in addition to a ballast used to stably light the high intensity discharge lamp, an igniter is attached to the high intensity discharge lamp so as to generate a starting high voltage.
FIG. 1 is a vertical sectional view of a conventional high intensity discharge head lamp for automobile in a vehicle side direction and is disclosed in Published Unexamined Japanese Patent Application H3-136938 (1991).
A reflector 2 having a function of a reflecting mirror is disposed in a housing 1 to converge and control a light beam, and an inner surface of the reflector 2 is coated to form a reflecting surface. A high intensity discharge bulb 4 held by a valve socket 3 is disposed in the almost center of the reflector 2. To light the high intensity discharge bulb 4, an igniter 5 generating a high voltage of 30 KV is disposed in a high intensity discharge lamp equipment. Here, a lighting control of a high intensity discharge lighting device is performed in a power supply control circuit (or a ballast) 7. In the above-described configuration of the high intensity discharge lighting device, a high voltage is applied to the high intensity discharge bulb 4 in a moment to induce a high voltage discharge of the high intensity discharge bulb 4, the discharge of gas packed in the high intensity discharge bulb 4 occurs, and the high intensity discharge bulb 4 is lighted. 8 indicates a lens. A beam of light of the high intensity discharge bulb 4 is dispersed in a prescribed area through the lens 8 and is radiated in a front direction of a vehicle. Therefore, the safety of the vehicle is secured during the running of the vehicle in the dark.
As is described above, a high intensity discharge lamp is disposed in a space between a bumper 9 and an engine hood 10. 11 indicates a harness electrically connecting the high intensity discharge lamp equipment and the ballast 7.
Also, 12 indicates a substrate on which the high intensity discharge bulb 4 is fitted. 13 indicates a transformer in which a primary coil and a secondary coil are wound, and a starting voltage of the high intensity discharge bulb 4 is generated in the transformer 13. 14 indicates a condenser for charging a starting energy. 15 indicates a discharge gap element. An electric potential difference occurs between both ends of the discharge gap element 15 when the discharge gap element 15 is charged by the condenser 14, the discharge of gas sealed in the discharge gap element 15 is started in a moment due to the dielectric breakdown of the gas, and current is carried to the primary coil of the transformer 13. Therefore, a high voltage pulse of a voltage ranging from 20 KV to 30 KV is generated in the secondary coil of the transformer 13, the electric discharge of the high intensity discharge bulb 4 is induced, and the lightening of the high intensity discharge bulb 4 is generated. 16 indicates a cap. Here, the igniter 5 is a general name of a starting device composed of the substrate 12, the transformer 13, the condenser 14 and the discharge gap element 15.
In the prior art described above, it is troublesome to wind the primary and secondary coils around a bobbin of the transformer 13. Therefore, the transformer 13 is not appropriate for the stabilization of a coil winding operation, the prevention of the broken coil, the protection of films coated on the primary and secondary coils, the production of a small-sized transformer and an automatic wiring operation.
The present invention is provided to solve the above-described problem, and the object of the present invention is to provide a transformer in which a shape of a bobbin is determined to perform an automatic coil wiring operation and which has a high reliability.